• Head movement instead of eye movement. The head should stay still. A student who swings their head to follow the numbers is compensating for weak eye muscles or poor control.
• Losing the place at the end of a line. The return sweep to the start of the next line is the hardest saccade in reading, and the most common failure point.
• Skipping or hunting. Eyes jump past the new number, then search back for it.
• Naming lag. The eye lands correctly but the name arrives late or not at all — that points to rapid naming rather than tracking.
• Fatigue across pages. Performance that is clean on page 1 and falls apart by page 3 is a real finding. Run at least three pages.
• Tint response. If accuracy improves noticeably on a tinted page, note it — that is a flag for the Irlen screening, not a conclusion.

This is an observation screening, not a diagnosis. It does not replace an eye exam. If flags appear, refer to a developmental optometrist or vision specialist. A student who cannot yet name digits 1–9 reliably should be taught those first — otherwise this measures naming, not tracking.